Sink stopper



Patented Sept. 30, 1952 UNITED STATES PATENT orrlcs Arthur G. Gross, Manhattan Beach, Calif. Application September 2, 1948, Serial No. 47,443

The present invention relates to drain stoppers for kitchen sinks, tubs, and the like, wherein the drain opening is covered by a perforated strainer disk and is therefore not adapted to receive a conventional tapered plug stopper. More specifically, the invention is concerned with flat, rubber disk stoppers of the type which are adapted to be positioned over the strainer disk, and which are held in place bythe pressure of the water standing thereon.

Prior drain stoppers of this general type have usually been made with a smooth flat contact surface on the underside thereof which is adapt-- ed to seat against the bottom of the sinkaround the margins of the drain opening in a watertight sealing engagement. It has generally been believed desirable to have the entire bottom surface of the stopper disk lie flat against the bottom of the sink, on the assumption that all of the disk area lying fiat against the sink bottom would be sealed thereto, and consequently subjected to water pressure. I have discovered that this is not the case, however, and that a smooth, flat-surfaced stopper disk tends to form a seal only along a relatively narrow marginal zone immediately adjacent the edges of the drain opening. It is only within the area enclosed by this sealing zone that the top and bottom surfaces of the disk are exposed to the pressure differential responsible for holding the stopper down against the sink bottom. This pressure differential results from the fact that the top surface of the disk is exposed to the water pressure, whereas the bottom surface of the disk, within the area bounded by the sealing zone, is exposed to the pressure prevailing in the drain opening. The area of the disk bottom lying outside of the sealing zone is cut oil from the drain opening, and is therefore not exposed to the pressure therein; hence such outlying area has no pressure differential between its top and bottom surfaces, and is therefore ineffective. In other words, the stopper is held down against the drain opening by the weight of a column of water standing only above the circular area enclosed by the sealing zone, which is usually considerably less than the total area of the disk. The resistance of the stopper to lateral displacement is a function of the downward pressure applied thereto, which is directly proportional to the cross-sectional area of the column of water standing on the disk. Thus, the downward pressure obtained with prior smooth-surfaced stoppers is inadequate to resist accidental lateral displacement satisfactorily because of the relatively 4 Claims. (01. 4-293) small efiective area enclosed by the sealing zone; hence it has been common practice to provide one or more projections at the center of the stopper disk that are adapted to fit into holesin the strainer ,to secure the stopper in place. Alining these projections with corresponding holes in the strainer disk is sometimes difficult to do, and the use of such projections is generally unsatisfactory, although the only previously known expedient capable of preventing displacement of the stopper.

The primary object of the present invention is to overcome these difiiculties by providing a drain stopper of the character described which is'so' constructed and arranged that the sealing engagement with the sink bottom occurs only at the outer periphery of the stopper, whereby the stopper is held down against the drain opening by a column of water covering the entire area of the stopper. This has the effect of greatly in creasing the downward force applied to the sink stopper, as compared with conventional drain stoppers, and results in a considerable increase in the resistance of the stopper to lateral displaceother selected embodiments showing various modifications of the invention. for which reference is had to the accompanying drawing, where- Figure l is a bottom plan view of a sink stopper embodying the principles of my invention;

Figure 2 is a sectional view, taken along the line 22 in Figure 1, illustrating the manner in which the drain stopper cooperates with the sink bottom and drain opening;

Figure 3 is a bottom plan view of another form of the invention;

Figure 4 is a bottom plan view of another modification; and

Figure 5 is a bottom plan View of still another form of the invention.

Reference is had first to Figures 1 and 2 of the drawings, wherein the sink stopper of the inven tion is seen to comprise a relatively thin circular disk H) of rubber or rubber-like plastic, which is adapted to be placed on a sink bottom I I to cover a drain opening I2. The drain opening I2 is usually covered by a perforated strainer plate l3 which is substantially flush with the sink bottom II, and the disk It) is preferably made sufficiently large in diameter to cover the strainer plate l3 and extend radially outward beyond the same for a, considerable distance. In the drawings, both the top and bottom surfaces of the disk are shownaslfunctional surfaces having configurations formed therein which cooperate with the sink bottom to accomplish the objects of the invention, as will be described in more detail presently, thereby enabling either side ofthe stopper to be placed face down on the sink bottom. However, it is also contemplated that the disk might be made with the bottom surface only serving as a functional surface, in which case the top surface would be inefiective, :andthe stopper would be operative only when right side up. a i

ormed aroundrthevonter peripheral edge -,of the disk It) is :an annular-sealing lip-i4 which may'take the form :of a round bead, as shown, oroany other suitable .Cl'OSSeSBCtiOlJ. This sealing lip l4 isadapted .to seatnnthe sink bottom II at l5, forming arcontinuous circular seal near the periphery of. the disk, :at aconsiderable distanceradially outwardgfrom' the margins of the drain opening 12. In order-to prevent the formation of a continuous seal at-anypoint lwithin'the area bounded 'byithelzsealing .lip HI, I provide means for venting the enclosed :area. to. the drain opening [2. This has-the: effect of-exposing substantially the entire bottom surface of-the disk to thepressure prevailing in the drainopening, which is usuallyatmospheric pressure or-less. Hence, the entire: areaiof the 1 disk is exposed .to the, pressure differential obtained on both sides thereof, and theldiskis held down against the sink bottom by a-vertical pressure equal to the weight of a column of waterofvthe same diameter as the disk.

Ventin the ,under side of the-diskto thedrain opening may beaccomplishedgby anyof-several methods,- the ,preferredmethod being shown in the embodiment of Figures 1, and 2, wherein the sealing surfaces are formed with shallow recesses l6- extending from .the inner edge of the :sealing lip in toward the.center;of the disk. The recess 16 may cover the entireareaof the-diskbounded by the sealing lip l4,-or, as'shown in the drawing, it may terminate at, araised circular boss '20 inthe center of-the dish-whichis adapted to bear on the strainer plate :13. Projecting-from the? bottom of theyrecessedareas l6,-concentric with the center tofrthe disk, .is a 'plurality of radially spaced,- circular ridges 2 which are broken at intervals to form radial channels 22. The ridges 2| hold. the recessed areafli out-of contact with the ,sink bottom ll orthemarginal flange of the drain opening, and the channels 22 vent the spaces (between adjoining ridges .2! to the drain opening I2. The outer-surfacesof the ridges 2i and boss 20, mayebe .flush with ,or lie slightly below the plane of. theoutersurface of the sealing lip. r

Another embodiment of the invention. is fillus trated in FigureB, wherein parts that are similar to those described in connection with vthe preceding embodiment are given;the,.samesreference numerals, with the sufdx a.

In this form of the invention. the bottom surface of the disk lilais substantiallyilat and has a circular outer channel-'2 formed therein a short distance in from the outer peripheral edge'of the disk. The narrow strip of disk lying beyond the channel 25 forms the sealing lip Ida which is adapted to form a seal with the bottom of the sink at a distance spaced radially outward from the margin of the drain opening thereof. A circular inner channel 26 is also formed in the underside of the disk concentric with the outer channel 25; said inner channel being disposed to overlie the drain opening 25 when the stopper is in use. ',Connecting the:outerchannel 25 with the inner channel 26 is a'pluralit'y of angularly spaced, radially extending channels 21. The channels 25, 26 and 21 serve to vent the underside of .the disk to the drain opening, and thereby prevent the formation of a continuous seal except at the line of contact of the sealing lip 14a.

Another form of the invention is illustrated in Figure 4, and in this embodiment, parts that are similar to those previously described are given the same reference numerals with the suflix b.

.Thebottom surface:of::the disk lob is recessed :at1301 from thejinneriedge zofdthe sealing lip Mb in. toward the center "of the disk, terminating .at its inner edge in a central, raised boss 2011.. A plurality of raisedgletters 3lmay be formed on the recessed area 30, presenting either atrademark,.or the company name -of the manufacturer, or both-,-.substantiallyas-shown, .In this 'case, the raised letters prevent the :recessedarea from lying flat against thesink-botto'm:andalso serve to vent the underside {of thedisk: to the drain opening l2; so "that theydiskzisgrpreventedfrom forming a. seal exceptxat the-line of contact 'of the sealing lip I 412.

- Figure 5 shows still another embodim'ent'of the invention, wherein;the:underside of disk l-Oc' is formed with a roughetextured surface35 between the annular sealinglip Moand central -boss20c. The textured-,surface.:35 maybe similar to that shown, or it may simulate zany c other :desiredsurface; the :only requisite being that minute connectingpassages be provided which ,servegto-yent the underside of the disk from the inner edge ofthe sealinglip ,to;the drain ODEIll-HQ'LSO asrto prevent the formation-of arSBal exceptrat the lineofcontact of the sealing lip.

In each of the foregoin embodiments, the basic principle is the same. r An annular sealingilip is provided around the outer periphery ofltheldisk, which-is adapted; torform a-seal with-the sink bottom at a considerable distanceradially-Outward fromthedrain opening l 2. Theentire area of=the disk enclosed within'the sealing-lip is then vented to the drain opening so--as:to .prevent the formationjof a continuouswsealexcept at the line -of-, contactof the-sealing. 711p. This insures that the-entirearea :of the drain stopper will be exposed to the-pressuredifference resulting from the weightof a-,column of :water standmg on the top surfaceof the disk, giving the maximum vertical pressurev obtainable on the stopper to holdflthesame down'asainst the sink bottom and drainppening. l The increased water pressure. on thesink stopper-gives the latter increasedresistance to lateral displacement; thereby eliminating the .need for ace'nteringtplug which has. heretofore be'en provided for the purpose of engaging in'th'je holes, of the, sink strainer l3 to prevent'displacement of the stopper. Additional resistance to lateral displacement of the tQDDer is also provided by the anti-skid tread effect produced bythe' channels orjridges of the several embodiments. While I have shown and described in considerable detail certain selected embodiments of "the invention," it is tobe understood that such details are not restrictive, and that various changes may be made in the shape and arrangement of the several parts without departing from the scope of the invention as defined in the appended claims.

I claim:

1. A drain stopper comprising a substantially flat disk of rubber-like material, raised sealing means adjacent the outer periphery of said disk adapted to form a seal with the bottom of a sink at a distance radially outward from the margin of the drain opening thereof, and means for preventing the formation of a continuous seal between the underside of said disk and said sink bottom at any point except at said sealing means, said means comprising raised sink-engaging elements formed on the area of said disk inside said raised sealing means, and air passageways between said elements extending from said sealing means inward to the disk area overlying said drain opening whereby the total head of water over the entire area of the stopper will exert a downward force upon the stopper to preclude slipping thereof with relation to the drain opening.

2. A drain stopper comprising a relatively thin, substantially flat disk of rubber-like material, and an annular sealing lip formed on said disk adjacent the outer periphery thereof, said sealing lip being adapted to cooperate with the bottom of a sink at a distance outwardly from the margin of the drain opening thereof to form a seal, the underside of said diskwithin the area bounded by said sealing lip being formed with a.

plurality of channels extending from said sealing lip in toward the center of the disk, said channels serving to vent the underside of said disk to said drain opening so as to prevent the formation of a continuous seal between said disk and said sink bottom except at the line of contact of said sealing lip whereby the total head of water over the entire area of the stopper will exert a downward force upon the stopper to preclude slipping thereof with relation to the drain opening.

3. A drain stopper comprising a relatively thin, substantially flat disk of rubber-like material, an annular sealing lip formed on said disk adjacent the outer periphery thereof, said sealing lip being adapted to cooperate with the bottom of a sink at a distance outwardly from the margin of the drain opening thereof to form a seal, the underside of said disk being recessed for an appreciable distance from said sealing lip in toward the center of the disk, and a plurality of interrupted projections raised from the surface of said recessed area, said projections serving to prevent said re-v cessed area from lying flat against said sink bottom and forming a series of connected passageways extending from said sealing lip in toward the center of said disk, whereby the underside of said disk is vented to said drain opening and is prevented from forming a continuous seal except at the line of contact of said sealing lip in such manner that the total head of water over the entire area of the stopper will exert a downward force upon the stopper to preclude slipping thereof with relation to the drain opening.

4. A drain stopper comprising a substantially flat disk of rubber-like material, a continuous sealing ridge on the underside of said disk adapted to form a seal with the bottom of a sink around the drain opening thereof, said sealing ridge defining a substantial disk area extending outside and entirely around the margin of said drain opening, and a non-sealing area on the underside of said disk between said ridge and an inner disk area which overlies the drain opening comprising a plurality of raised sink-engaging elements and intervening air passages extending from said ridge to said inner disk area, whereby the total head of water over the entire area of the stopper will exert a downward force upon the stopper to preclude slipping thereof with relation to the drain opening.

ARTHUR G. GROSS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 229,467 Remhof June 29, 1880 950,574 Morgan Mar. 1, 1910 1,613,158 Brewer Jan. 4, 1927 1,710,878 Kelso Apr. 30, 1929 1,912,312 Schacht May 30, 1933 2,237,546 Butt Apr, 8, 1941 2,289,498 Hons, Jr. July 14, 1942 2,425,964 Smith Aug. 19, 1947 

